Ch.32 Bio 182

What are the three 'subphyla' within the Chordata? What familiar organisms do the Cephalachordates resemble? Which one includes the ecologically important salps?

1. Cephalochordates 2. Urochordates 3. Vertebrates

What are some of the advantages of retaining the embryo within the body of a mother?

1. Develop at a more constant, favorable temperature 2. Protection 3. Offspring are portable - Mother is not tied to nest

There are four phyla within the deuterostomes. Which ones are we going to cover? Which ones includes the vertebrates?

1. Echinoderms 2. Hemichordes* 3. Xenoturbella 4. Chordates*

Feathered dinosaurs: List three adaptations for flight that birds have

1. Keel - bird sternum has a projection that provides a large surface area with flight muscles attached 2. Birds are light for their size: Reduced number of bones Large bones are thin-walled and hollow 3. Birds are endothermic—they maintain a high body temperature by producing heat in their tissues

In which three groups has flight evolved independently? Ground up or from trees down?

1. Pterosaurs, extinct flying reptiles 2. Bats 3. Birds

Vertebrate brain: this key innovation consists of three distinct regions- forebrain, midbrain and hindbrain. Which part is modified into a cerebellum and medulla oblongata in all jawed vertebrates. The cerebrum is a part of the ____________ that is enlarged in birds and mammals. What is the adaptive significance of the brain?

1. hindbrain 2. forebrain

What are the four morphological features that all chordates have at some point in their life cycle?

1.Openings into throat called pharyngeal gill slits 2.A dorsal hollow nerve cord that runs length of body, comprised of projections from neurons 3. A stiff and supportive, but flexible, rod, called the notochord, that runs the length of the body 4. A muscular post-anal tail

Aves (birds): about how many species? How does this compare the number of species of other reptiles? What do birds eat? How is their diet correlated with their beak shape and size?

10,000 around 1/3 Plant-eaters that feed on nectar or seeds Omnivores Predators that feed on insects, mammals, fish, other birds, lizards, and invertebrates Size and shape of beak correlated with diet

Crocodilia: how many species are there and where are they found? What do they eat? Do they have parental care? Dinosaurs: DO they have parental care?

24 species of crocodile and alligator Most are tropical; live in freshwater or marine environments All crocodilians are predators; amphibians, turtles, fish, birds, and mammals Crocodilians are oviparous; parental care is extensive Young can hunt when newly hatched but stay near their mother for up to three years there is some evidence for prenatal care in dinosaurs

Turtles and tortoises: how many species are there? what does the skull of turtle lack? What is the difference between a turtle and a tortoise? Aquatic species have feet modified into flippers. What is a main food item of marine turtles?

320 species of turtles and tortoises lack teeth marine turtles are carnvivorous- jellyfish tortoises are herbivores

Marsupiala (kangaroos, wallabies and koala) About how many species are there and where are they found? {Please briefly describe how they reproduce

350 species found in Australian region and Americas reproduce sexually

eutherians (placental mammals) about how many species and where are they found? Which group is the sister group to the primates? Which group is the sister group to the cetacea?

5100 species of eutherians

Echinoderms: how many species and where are they found? What three important synapomorphies define this group? Please briefuly describe each synapomorphy and how it is an important adaptation, How are tube feet used in feeding

7000 species of echinoderm All echinoderms are marine animals; abundant in deepwater environments Echinoderms are monophyletic with three important synapomorphies 1. Radial symmetry in adults 2. An endoskeleton of calcium carbonate 3. A water vascular system

Snakes and lizards: how many species are there? What do they eat? How do they reproduce?

8900 species of lizards and snakes - with elongated bodies and scaly skin Small lizards tend to be predators, but large ones are often herbivorous Most reproduce sexually But asexual reproduction via parthenogenesis in six lizard groups and one snake lineage

Some reptiles are ectothermic, while others are endothermic. Please give an example of each. How do the ectothermic reptiles regulate their body temperature?

All reptiles are ectothermic (except birds) They Internally generated heat is not used to regulate body temperature Moderate their body temperature behaviorally for ex. by basking in the sun

How many membranes does the ambiotic egg have? What are their two important function? Briefly describe the over all functional significance of the amniotic egg

Amniotic eggs - external membrane plus three internal membranes Provide mechanical support Membranes increase surface area for gas exchange Amniotic eggs - Reptiles, birds, and egg-laying mammals lay these eggs outside of water Protection from desiccation and predation (to some extent)

Which phyla include invertebrates? Are invertebrates a monophyletic group? why or why not?

Chordates

Briefly describe the two types of evidence for the hypothesis that tetrapods limbs evolved from fish fins?

Fossil record indicates a gradual transition from a lobe-like fin to a limb that could support walking on land (see Figure 35.16) Regulatory gene expression (Hox genes) produce proteins found at the same times during development and in the same locations in fins and limbs

The eutherian mammals have several features of their reproductive life that help to increase the survival and success of their offspring. What are they?

Internal fertilization and are viviparous Young are much better developed at birth than marsupial young, due in part to an extensive placenta Some young are able to walk or run minutes after birth Feed their offspring milk Often have a period of parental care that extends beyond the nursing stage Some species are highly social

Cichlid fish are very common in freshwater habitats in Africa and Central and South America. What are the names of two large freshwater lakes that they are found in? How many species in each lake? What is one obvious way that species vary in appearance?

Lake Victoria- 300 species

Monotremes (platypous and echidna) About how many species are there are where are they found? They lay eggs but do they nurse their young? Where do they lay their eggs? Are they carnivores or herbivores?

Only five species - one platypus and four species of echidna; found only in Australia Lay eggs and have low metabolic rates Eggs hatch quickly Mother keeps them warm /dry for four more months Monotremes produce milk and nurse their young Platypuses feed on small animals in streams Echidnas feed on ants, termites, and earthworms on land

What is a pharyngeal jaw? What is it used for in most fish specieis

Pharyngeal jaw - specialized jaw found in several lineages of ray-finned fishes most fish use them to push food down throat, but some fish use them for more specialized purposes

Which group is the amniotic egg a synapomorpy for? In other words, this group is all tetrapods except for _______. Which familiar animals are in that group?

Platypus

Placcenta: Note the similar membranes to those of an amniotic egg. Briefly describe its function. Note that the placenta has a fetal and maternal derived part

Rich in blood vessels Facilitates flow of oxygen and nutrients from mother to embryo Facilitates removal of nitrogenous wastes and carbon dioxide from embryo

Vertebrates: the dorsal hollow nerve cord is modified into what important structure? What does the notochord do in vertebrates?

Spinal cord. Notochord helps organize the body plan early in development by secreting proteins that induce somite formation

Consider each membrane separately: What is the function of the outermost membrane (chorion)? One of the inner membranes has a function of storing waste from the embryo. Which is it? Which membrane surrounds the embryo itself?

Three inner membranes surround Embryo itself (amnion) Yolk provided by mother (yolk sac) Waste from embryo (allantois)

Mammals: What the three synapomorphies that define mammals? What is the significance of each? What are the three lineages of mammal and how are they different with regard to reproduction?

Three synapomorphies for mammals: 1. Hair or fur—used for insulation 2. Endothermy Mammals regulate their body temperatures with internally generated heat 3. Mammary glands for lactation Evolution of mammary glands gave mammals the ability to provide their young with extensive maternal care Three mammalian lineages: 1. Monotremata (platypuses, echidnas) Monotremes lay eggs Marsupiala (marsupials) 2. Marsupials - a poorly developed placenta but well-developed pouch for rearing offspring 3. Eutheria (placental mammals) Eutherians have a well-developed placenta and extended pregnancy

Fish consist of six lineages and are a praphyletic group, but the largest group of fishes, the ray-finned fishes, is monophyletic. a. How many species of ray-finned fish are there? b. How does this compare with the number of bird species, with the number of mammal species? c. Are there more mammal species or more snake species?

a. 30,500 b. around 3x more than bird species, bird species 10,00, around 6x more than mammals; 5,500 c. more snakes

Parental Care: What is the fitness trade off of parental care? Which organisms have parental care? Lactation can also be part of parental care, but this trait is confined to mammals.

any action by a parent that improves ability of its offspring to survive Extensive parental care requires a fitness trade-off Fewer offspring produced But offspring more likely to survive

Ray finned fishes: this is the most successful vertebrate lineage. Teleost fishes comprise almost all of the ray-finned fish. What is a swim bladder?

derived from early lungs) provides buoyancy

Amphibians: Please review their basic characters. What kind of eggs do they lay? What are the three monophyletic groups within amphibians?

lay their eggs in water 1. Frogs and toads - sit and wait predators with extensible tongues; oviparous with external fertilization 2. Salamanders - active predators; internal fertilization; most are oviparous 3. Caecilians - lack limbs and resemble snakes or worms; burrow underground in wet tropical regions; have internal fertilization; many are viviparous

Reptilia: Are reptiles a monophyletic group? Why or why not? There are four major, modern lineages of reptiles: lizards and snakes, turtles, crocodilians and birds. What are some of the basic adaptions to terrestrial life found in Reptiles and how are they advantageous?

monophyletic group 1. Skin is watertight via a layer of keratinous scales 2. Breathe air through well-developed lungs 3. Lay amniotic eggs enclosed in shells

What is unusual about the early diverging fish, hagfish and lampreys?

only living jawless vertebrates

Are fish a monophyletic group? Please explain. Which six groups can be called fish?

paraphyletic 1. Myxinoidea (hagfish) - only living jawless vertebrates 2. Petromyzontoidea (lampreys) - as above 3. Chondrichthyes (sharks, rays, and skates) 4. Actinopterygii (ray-finned fishes) - very diverse include 5. teleost fish (most common of the ray-finned fish) 6. Actinistia (coelocanths) Dipnoi (lungfish) - sister group to tetrapods

Primates: the prosimians and the anthropoid apes are the two main lineages of primates. Which lineage diverged first? What is the relationship of chimps, humans, and gorillas? In other words, which is the sister group of humans? Or phrased another way, which of the three diverged earliest?

prosimians great apes

What are some of the different types of food that the cichlids eat? How do the pharyngeal jaws help with specialization of type of food ingested?

snails, fish scales, compacts algae trematocrnus placodon- crushes snails coremtodus taeniatus- tears fish scales labeotropheus fuelleborni- compacts algae Overall, feed on almost every conceivable food source in the lake But most species specialize on one of the following food items: Planktonic organisms, algae on rocks, algae with leaflike blades, eggs, fish scales, fish fins, whole fish, plants, insects, and snails

Sharks: lack a bony endoskeleton and instead have a cartilaginous skeleton. What do they feed on and where are they found?

suspension feeder and feeds on plankton

Vertebrates have two important synapomorphies: Vertebrae and a cranium. What is the adaptive significance of each of those traits?

vertebrae- protects the spinal cord Cranium- protects the brain and sensory organs

Are the deuterostomes a monophyletic group?

yes